CZ225593A3 - Catalyst and method of ethylene and other alpha olefins polymerization - Google Patents

Abstract

A catalyst active in the polymerization of alpha-olefins is formed by: (a) a bis(cyclopentadienyl) bis(amide) derivative of an element of Group IVB of the Periodic Table of the Elements, to be defined by means of the formula : <CHEM> wherein M represents a metal of Group IVB, each of R<1>, R<2>, R<3> and R<4>, and Cp have the same meaning as reported in the disclosure, and (b) an aluminoxane co-catalyst. This catalyst finds use in the processes of ethylene and other alpha-olefins polymerization and copolymerization.

Description

Catalyst and process for the polymerization and copolymerization of ethyl and other alpha-olefins

Technical field

The invention relates to a catalyst comprising a bis (cyclopentadienyl) bis (amide) derivative of elements IV. B groups of the Periodic System of Elements and aluminum oxane as a cocatalyst, in the process of copolymerization and polymerization of ethylene and other aluminum olefins.

BACKGROUND OF THE INVENTION

It is known in the art that the polymerization of ethylene, generally alkali ols, takes place under reduced pressure using Ziegler-Natta catalysts,

Catalysts which contain a transition metal compound (Group IV-VIII elements of the Periodic System of Elements) in admixture with an organometallic compound or a hydride of elements I-III are useful. groups of the periodic system. The catalysts are functional in suspension or solution, but also in the absence of a solvent or diluent. For a reference to this polymerization process, see J. Boor (J. Boor Ziegler - Natta Catalysts and Polymerization, Academic Press, New York, 1997).

A special class of catalysts active in the olefin polymerization process consists of the combination of aluminum oxane with a cyclopentadienyl derivative of such elements as titanium, zirconium and haium (IV. B group). These derivatives are called metallocenes and are defined by the following general formula II,

Op R \ (II),

Op r ~; o> c? to C— ¹ j

Z>

o <= ΰ o

σι x o <

LC where M is metal IV. B groups of the Periodic Table of the Elements, each R is a halogen atom, an alkyl group or an aryl group and each Cp is independently a cyclopentadienyl, indenyl or fluorenyl group (see H. Sinn, V. Kaminsky's description in Adv. Organomet. Chem. 18, 99, for reference) (1980) and U.S. Patent Properties, Composition and Number 4542199).

These catalysts exhibit a high catalytic activity and the ability to form polymers with the desired characteristic role of the precise catalytic or olefin composition used as the role of olefin polymerization (reference, e.g., see the disclosures of U.5. Nos. 4530914, 4935474, 4937299 and 5001205 and published European patent applications Nos. 35242, 318049, 384171 and 387609).

The present inventor has discovered, according to the present invention, that these catalysts, especially metallocenes containing amide groups in their molecular structure, are used together with aluminum oxanes, resulting in catalysts extremely active in the olefin polymerization process.

Therefore, it is an object of our invention to provide a catalyst that comprises an amide-substituted metallocene and an aluminum oxane.

It is also an object of the present invention to describe a process for the polymerization and copolymerization of ethylene and other alolefins using a given catalyst.

Further objects of our invention are apparent from the following description of the invention.

SUMMARY OF THE INVENTION

The present invention provides a catalyst for the polymerization of ethylene and other alpha-olefins, comprising:

a / bis (cyclopentadienyl) bis (amide) derivatives of elements IV. Class B of the Periodic System of Elements described by General Formula I, (I)

Cp

NB ¹ SS

Cp / \

NR ³ R <

wherein M represents metal IV. B groups of the periodic system of elements,

B ¹ . R _f 3 _and H 4 are independently alkyl having 1 to 8 carbon atoms, cycloalkyl having 5-8 carbon atoms or íenylovou group, and each Cp independently represents a cyclopentadienyl, indenyl or fluorenyl group, possibly bearing at least one C1-4 alkyl substituent. The aforementioned Cp groups can also be linked to each other by a bridged carbon atom structure or an alkyl silane structure. b) aluminum oxane as a co-catalyst

It is particularly suitable for the metal M in the aforementioned general formula I to be selected from the group comprising titanium, zirconium and haium, preferably zirconium and hafnium.

It is further preferred that R 1, R ² , R ³ and P ⁴ , as previously defined in formula I, independently of one another are C 1-4 alkyl groups. More preferably, all R ¹ -R ^{4 are} ethyl.

In the above formula I, Cp is preferably selected from a cyclopentadienyl, indenyl and fluorenyl group which may not be substituted or may carry at least one C 1-4 alkyl substituent. If both Cp groups in the compound of formula I are linked by a bridging structure, it is preferable to have a bridging structure which is characterized by being a linear or branched alkylene group having 1;

-4 carbon atoms or, preferably, dimethylsilyl. Examples of such bridged groups are

-4 bis (cyclopentadienyl) ethylene, bis (indenyl) ethylene, bis (cyclopentadienyl) dimethylsilyl and (cyclopentadienyl-1-fluorophenyl) isopropyl.

• Λ

Specific examples of compounds of formula I are thus: bis (cyclopentadienyl) -bis (ethylamide) zirconium, bis-cyclopentadienyl) bis (ethylamide) hafnium, ethylene-bis (indenyl) bis (ethyl amide) __ zirconium, ethylene-bis (indenyl) - bis (ethylamide) hafnium and isopropyl 1 (cyclopentadienyl-fluorenyl) -bis (ethylamide) hafnium.

In these catalysts for the production of polyolefins with a broad molecular weight distribution, a compound of the formula I containing two different metals M may be used.

A compound of formula Ϊ in which both Cp radicals are cyclopentadienyl groups and all R ¹ -R ⁴ are ethyl groups can be prepared as described by G. Chandra and MF Lapper published in J. Chem. Soc. (A), 1968, 1940.

According to our invention, the aluminum oxane ¹ in combination b with the above-mentioned compound of formula I is used as a co-catalyst.

As is known, aluminum oxanes are compounds containing an Al-O-Al bond with varying 0: Al atoms. They can be obtained after the reaction of the aluminum alkyl or the aluminum alkyl halide with. under controlled conditions, with water or, in the case of trimethylaluminum, also with a hydrated salt such as. aluminum sulphate hexahydrate, copper sulphate pentahydrate or iron sulphate pentahydrate.

In the case of our invention, the above aluminum oxane and the compound of formula I are contained in our catalyst in amounts such that the ratio of the aluminum atoms in the aluminum oxane and the metal atoms IV, B of the Periodic Table of the elements contained in the compound of formula I ' range 10 1 - 10 ®: 1, preferably for the ratio 10 ² : 1 - 10 ⁴ : 1.

Catalytic system 'according to our' invention is 'advantageous' for .....

polymerization of ethylene with linear polyethylene as the product of the reaction; and for the polymerization of propylene or higher alpha-olefins, resulting in the production of atactic, syndiotactic and isotactic polymers. Furthermore, the catalyst system is effective in copolymerizing ethylene with propylene (or other olefins (CLLDPE formation)) and in terpolymerizing ethylene with propylene and diene.

The polymerization is carried out by a slurry technique in an inert solvent or in a gas phase, with a temperature maintained in the range of 20-120 ° C and a pressure of 100-30,000 kPa. A molecular weight regulating agent is used, which is, for example, hydrogen.

DETAILED DESCRIPTION OF THE INVENTION

The following experimental examples are provided to better illustrate the invention.

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Example 1

A five-liter Bringole pure steel autoclave, equipped with a magnetically controlled injection trigger and electric temperature control resistors, is filled with the following components:

n-hexane (degree of polymerization) 1900 ml

Catalyst Cp 3 Zr [N (C 2 H 5) 2] 0 .00752 g. . co-catalyst (MAO * 103 solution in toluene) 40 ml ₃ . . a molecular weight regulating agent _{in a} weight (Hz) of 50 kPa

... ethylene 1,443 MPa (*) MAO is an oligomer of aluminum methyloxane

The polymerization is carried out at an Al: Zr ratio of 2500: 1, maintaining a total pressure of 1.5 MPa and at a temperature higher than 70 ° C. The polymerization time is 1 hour. While maintaining these conditions, 0.258 kg of polyethylene is obtained with a yield of 34.4 kg of polymer per 1 g of catalyst, which corresponds to a yield of 138 kg of polymer per 1 g of zirconium contained in the catalyst.

- b Example 2

The ethylene polymerization proceeds in the same manner as in Example 1 above, with the following changes:

Catalyst, Cp 2 ZrIN 2 Cl 2 H 2 O 2 0.00191 g

co-catalyst (MAO solution 10¾ by weight in toluene) 8.77 ml

The polymerization was carried out for 1.5 hours at an Al 'Zr ratio of 2500: 1. Under these conditions, 0.1625 kg of polyethylene could be obtained with a yield of 85 kg of polymer per g of catalyst, corresponding to a yield of 341 kg per g of zirconium contained in the catalyst.

Example 3

The ethylene polymerization proceeds in the same manner as in Example 1 above, with the following changes:

Catalyst CP2 Zr [NCC2H®] zz 0.002 9

co-catalyst (solution of MAO 10 wt.% in toluene) 11 ml

The polymerization was carried out for 16 hours at an Al: Zr ratio of 2500: 1. Under these conditions, 0.198 kg of polyethylene was obtained with a yield of 99 kg of polymer per g of catalyst, corresponding to a yield of 398 kg of polymer per g of zirconium contained in the catalyst. The polyethylene obtained has a flow melt index (ASTM D 1238 E) of 1.78 g / 10 min.

Example 4

The polymerization of ethylene takes place in the same reactor as in Example 1, with the following conditions:

- n-hexane (degree - polymerization) --------- - 1900. ml. . ...........

Catalyst Cps Zr [NiCa H &lt; + &gt;] Jz 0.001 g. co-catalyst (MAO 10 Si solution in toluene)

5.1 ml i

- 7 Glue regulating molecular weight (Ha) ethylene kPa 1,45 MPa

The polymerization takes place for 1.5 hours at an Al Zr ratio of 2500: 1, at a total pressure of 1.5 MPa and at a temperature of 70 ° C. Under these conditions, 0.166 kg of polyethylene is obtained with a yield of 166 kg per 1 g of catalyst. corresponding to a yield of 664 kg per g of zirconium contained in the catalyst.

The polyethylene thus obtained exhibits the following characteristics:

. . flow melt index (ASTM D 1238 Ξ)

.. flow melt index (ASTM D 1238 F)

.. shear sensitivity

.. density (at 23-C)

80 g / 10 min 167 .5 g / 10 min 19

O. 9630 g / ml

Example 5 ..

The ethylene polymerization is carried out in the same reactor as in Example 1 with the following conditions

n-hexane (degree of polymerization) 1900 ml

Catalyst CP2 Zr [N (C2 H5) 2 from 0.0007 g

co-catalyst (10% MAO solution in toluene) 3.8 ml. . a molecular weight regulating agent (Ha) of 50 kPa. . ethylene 1.45 MPa

The polymerization was carried out for 1.5 hours at an Al atomic ratio at a total pressure of 1.5 MPa, and at 40 DEG C. under these conditions, 0.166 kg of polyethylene polymer was obtained per g of catalyst, corresponding to the yield of g of zirconium contained in the catalyst.

Zr, 2500: 1, while maintaining a yield of 33 kg 132 kg per l

The polyethylene thus obtained exhibits the following characteristics: flow melt index (ASTM D 1238 E) 6.01 g / 10 min

- with a flow melt index (ASTM D 1238 F) 1662 g / 10 min. . sensitivity, at stroke 27 ^ 1

1900 ml 0.0007 g

3.8 ml kPa 1.25MPa

Example 6

The polymerization of ethylene is carried out in the same reactor as in Example 1, with the following steps: - - - - - - -

.. n-nexane (degree of polymerization)

.. catalyst Cp2 Zr [N (Cz Hs) 2]:

,. co-catalyst (10% MAO solution in toluene)

....... Molecular weight control (Hs)

.. ethylene

The polymerization takes place for 1.5 hours at an Al: 2r, 2500: 1 atomic ratio, at a total pressure of 1.5 MPa and at a temperature of 120 ° C. While maintaining these conditions, 0.0333 kg of polyethylene is obtained with a yield of 48 kg of polymer per Ig catalyst corresponding to a yield of 191 kg of polymer per g of zirconium contained in the catalyst

The polyethylene thus obtained has a flow melt index flow melt index shear sensitivity. density i at 33 in the catalyst.

^the following characteristics: i ASTM D 1238 E) 4.12 g / 10 min ASTM D 1238 F) 72.3 g / 10 min

17.6

0.9517 g / ml

Claims (4)

PATENT CLAIMS CLAIMS 1. Catalyst for the polymerization and copolymerization of ethylene and other alole-olefins, characterized in that it comprises an alpha / bis (cyclopentadienyl) bis (amide) derivative of element IV. B of the Periodic Table of the Elements of Formula I Cp NR 1 R 2 wherein M represents metal IV. B groups of the periodic system of elements; E ¹ , R ² , R ³ and R ⁴ are each independently an alkyl group of 1 to 2 C8, C5-C8 cycloalkyl or phenyl and each Cp independently of one another is cyclopentadienyl, indenyl or ilorenyl, optionally bearing at least one C 1-4 alkyl substituents of the above Cp group may also be linked to each other by a bridged structure carbon atoms or a silane structure of ab / oxane aluminum as a co-catalyst Catalyst according to claim 1, characterized in that it comprises a derivative of the general formula I, wherein the metal M is selected from the group consisting of titanium, zirconium and haium, preferably zirconium and haium. 3. A catalyst according to claim 1, characterized in that ^R, R @ 3 and R ⁴ in formula I are independently C 1-4 alkyl group being most preferred if all represent ethyl groups. 4. Catalyst according to claim 1, wherein the residue Cp in the general cyclopentadienyl, indenyl or which may not be substituted, but which may be represented by the formula X is either a fluorophenyl group, bear at least one C1-4 alkyl group substituent. or both of the two (Cp) groups may be joined together with bis (cyclopentadienyl) ethylene, bis (indenyl) ethylene, cyclopentadienyl-1-fluorophenyl) isopropyl and bis (cyclopentadienyl) - dimethylsilyl group. Catalyst. according to claim 1, characterized in that said compound of formula (I) is selected from: zirconium bis (cyclopentadienyl) bis (ethylamide), zirconium bis (cyclopentadienyl) bisethylamide, ethylene-bis (indenyl) bis (ethylamide) zirconium, ethylene-bis (indenyl) -benzethylamide) haine and isopropyl (cyclopentadienyl-fluorenyl) bis (ethylamide) haine. O. The catalyst of claim 1, wherein the ratio of the aluminum atoms contained in the co-catalyst (b) to the metal atoms IV. B group present in the compound of formula II is in the range from 1 to 10 ·· L0 ^e: 1, preferably between 102 and 10 "1. 7. A process for the polymerization and copolymerization of ethylene and other alpha olefins. The catalyst according to claims 1 to 6 is used.